Title:
SOFT MAGNETIC MATERIAL, METHOD FOR PRODUCING SAME, AND ELECTRIC MOTOR USING SOFT MAGNETIC MATERIAL
Document Type and Number:
WIPO Patent Application WO/2020/166115
Kind Code:
A1
Abstract:
A plate-like or foil-like soft magnetic material having high saturation magnetic flux density, which contains iron, carbon and nitrogen, while comprising martensite that contains carbon and nitrogen and γ-Fe where a phase that contains nitrogen is formed. This soft magnetic material is produced by a process wherein: a plate-like or foil-like iron-based material is heated and carburized with use of a carburizing gas; a particulate carbide is dispersed in α-Fe of the iron-based material at a temperature that is not higher than the eutectoid temperature; the α-Fe is transformed into γ-Fe at a temperature that is higher than the eutectoid temperature; nitrogen is diffused into the γ-Fe with use of a nitrogen supply gas, thereby forming γ-Fe-N-C; and the γ-Fe-N-C is transformed into martensite by being rapidly heated and subsequently quenched. Consequently, a soft magnetic material which has a higher saturation magnetic flux density than pure iron, while exhibiting thermal stability is able to be produced at low cost; and the characteristics of a magnetic circuit such as an electric motor are enhanced by using this soft magnetic material, thereby enabling the electric motor or the like to achieve a smaller size, a higher torque and the like.
Inventors:
KOMURO MATAHIRO (JP)
SATSU YUICHI (JP)
HATOU HISAMITSU (JP)
PARK SEUNGHWAN (JP)
SATSU YUICHI (JP)
HATOU HISAMITSU (JP)
PARK SEUNGHWAN (JP)
Application Number:
PCT/JP2019/035654
Publication Date:
August 20, 2020
Filing Date:
September 11, 2019
Export Citation:
Assignee:
HITACHI LTD (JP)
International Classes:
C22C38/00; C21D1/06; C21D6/00; C23C8/34; H01F1/147
Foreign References:
| JP2005002381A | 2005-01-06 | |||
| JPH09143635A | 1997-06-03 | |||
| JP2017166010A | 2017-09-21 | |||
| JPH07118703A | 1995-05-09 | |||
| US20160042849A1 | 2016-02-11 |
Other References:
TAKAHASHI, MIGAKU ET AL.: "New soft magnetic material of a' -Fe-C with high Bs", JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol. 239, 3 January 2002 (2002-01-03), pages 479 - 483, ISSN: 0304-8853
Attorney, Agent or Firm:
POLAIRE I.P.C. (JP)
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